Paul Cannell demonstrated yesterday he is a man of his word.

The free-spirited striker, who said he would be scoring goals if he were starting, broke open a defensive struggle by heading in a goal early in the second half to help the Washington Diplomats dispose of the Tulsa Roughnecks, 2-0, in a North American Soccer League game before 7,670 at RFK Stadium.

Cannell who had the dubious honor of leading the NASL in fouls and yellow cards (cautions) last year, also enhanced his reputation as an intimidator of goalkeepers to assist on the clincher.

Cannell shadowed Roughneck goalie Colin Boulton before stealing the ball and passing off to Alan Green. The slippery winger quickly converted Cannell's pass into his fifth goal of the year to give the hosts a 2-0 lead with 5:32 remaining.

"Good goalies don't make those kinds of mistakes," said a happy Cannell. "I think he was half watching me and half watching the ball. He dropped it and I kicked it away. I just said, 'Cheers, thanks.'"

Before Cannell's heroics, the Dips appeared content to play cat and mouse with the Central Division leaders. Tulsa came into the game averaging almost four goals a game, the NASL's highest scoring team. But the Roughnecks never pressed on offense and took only four shots, a Washington club record for fewest shots attempted by an opponent. While Washington took 19 shots. Diplomat goalie Bill Irwin made only one save.

Dejected Tulsa Coach Alan Hinton, sitting in the dressing room staring at the final statistic sheet, didn't believe his offensive-minded team took only four shots.

Washington's first goal was set up by two beautiful passes by Stokes and defender Tommy O'Hara. Stokes laid off a soft pass to O'Hara, who lofted a high pass over the Tulsa goal.

Cannell, an excellent leaper, simply outjumped defender David Nish and pushed a header over Boulton's head into the left side of the net to give the Dips a 1-0 lead at the 52:43 mark.

"It's my fourth assist in six games," said O'Hara, who plays as much offense as he does defense. "With Paul in there now, we can send the high balls up there. We couldn't do that before."

Even after falling behind, the Roughnecks never changed their tactic of all defense.

"I've never had a game so easy," OHara said. "They came here hoping for a tie and a shootout. We had so little pressure in the back, it was unbelievable."

Boulton, who was credited with three saves, will remember being duped by the clever Cannell for some time. The English keeper had taken a pass back from one of his teammates and was preparing to boot the ball upfield. But Cannell, who never leaves the goal area until the ball is gone, stood next to Boulton as if daring him to kick.

Boulton dropped the ball right in front of him and the quick Cannell stole it away and slipped it to his right to Green.

Green waited until Boulton got back in position before blasting the ball past him into the same spot as Cannell's goal to wrap up the game.

"The first goal was a typical Cannell goal," Bradley said. "Another good thing about Cannell is that he's so aware of what's going on around him. When Boulton bounced the ball, Paul was in like an arrow."

Washington raised its record to 4-2 and picked up eight points for a total of 36. The Cosmos defeated Philadelphia 4-2, for their fifth win of the year and remained in first place ahead of Washington in the National Conference's Eastern Division with 44 points.

"We just ran them over the place," Cannell said. "And, we'll get better and better. But you know the best thing about the game, I didn't get a yellow game."

Washington midfielder Joe Horvath was kicked in the left leg and left the game late in the second half, but his injury was not considered serious. Starting midfielder Jim Steele, nursing a bad knee, also left the game in the second half. CAPTION: Picture 1, Alex Skotarek of Tulsa heads the ball away from his own goal as netminder Colin Boulton watches flight; Picture 2, Paul Cannell (9) heads in the ball for a Diplomat goal. Photos by Linda Wheeler-The Washington Post